xhci: Increase STS_SAVE timeout in xhci_suspend()

commit ac343366846a445bb81f0a0e8f16abb8bd5d5d88 upstream.

After commit f7fac17ca925 ("xhci: Convert xhci_handshake() to use
readl_poll_timeout_atomic()"), ASMedia xHCI may fail to suspend.

Although the algorithms are essentially the same, the old max timeout is
(usec + usec * time of doing readl()), and the new max timeout is just
usec, which is much less than the old one.

Increase the timeout to make ASMedia xHCI able to suspend again.

BugLink: https://bugs.launchpad.net/bugs/1844021
Fixes: f7fac17ca925 ("xhci: Convert xhci_handshake() to use readl_poll_timeout_atomic()")
Cc: <stable@vger.kernel.org> # v5.2+
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/1570190373-30684-8-git-send-email-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index f28ea3c..202c806 100644 (file)
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -981,7 +981,7 @@ int xhci_suspend(struct xhci_hcd *xhci, bool do_wakeup)
        command |= CMD_CSS;
        writel(command, &xhci->op_regs->command);
        if (xhci_handshake(&xhci->op_regs->status,
-                               STS_SAVE, 0, 10 * 1000)) {
+                               STS_SAVE, 0, 20 * 1000)) {
                xhci_warn(xhci, "WARN: xHC save state timeout\n");
                spin_unlock_irq(&xhci->lock);
                return -ETIMEDOUT;